在复合句中, 修饰名词或代词的从句叫定语从句,被修饰的名词或代词叫先行词,引导定语从句的有关系代词 who, whom, whose, which, that等和关系副词where, when, why等,关系代词和关系副词在定语从句中担任句子成份。
1.由who引导的定语从句中,who用作主语, 如:This is the boy who often helps me.
2.由whom引导的定语从句中,whom用作宾语,如:The man whom you are waiting for has gone home.
3.由whose引导的定语从句中,whose用作定语 ,如 :Do you know the girl whose skirt is white?
The book that I bought yesterday was written by Lu Xun.
6.由when, where, why引导的定语从句,如:
I don't know the reason why he was late.
This is the place where we have lived for 5 years.
I'll never forget the day when I met Mr Li for the first time.
注意:先行词是表示地点时,如果从句的谓语动词是及物的,就用 that(which),如果从句的谓语动词是不及物的,就用where引导。This is the house Which /that he has lived in for 15 years.(Where he has lived for 15 year.)
(1)限制性定语从句是句中不可缺少的组成部分,主句和从句之间不用逗号分开。引导非限制性定语从句的关系代词有who, whom, whose, which, of which等,这些关系代词都不能省略。
(2)非限制性定语从句是对主句先行词的补充说明,没有这种从句,不影响主句意思的完整,一般用逗号把主句和从句分开, 关系代词用 which,不用that;指人时可用who,如 :I have two brothers, who are both students.